Change And Significance Of Aquaporin-4 In The Infant Rats Brain Edema Induced By Lipopolysaccharide

OBJECTIVE: Brain edema is one of the major pathologic changes of central nervous system (CNS), including cytotoxic edema and vascular edema. The mechanisms of infectious brain edema are very complex, many causes are involed. The time course of brain edema has close correlation with impairment of CNS, however, we have not understood the molecular biology mechanism of infectious brain edema. Following the discovery and deep research of Aquaporin (AQP), we have understood that Aquaporin-4(AQP4) have close correlation with brain tissue edema. The infectious brain edema was established by applying lipopolysaccharide (LPS) carotid injection in our experiment. On the basis of brain edema, the change of brain water content, Evens blue (EB), AQP4 and AQP4mRNA are monitored. The regularity of brain edema proceed is discussed, and the relationship of brain edema and AQP4 is researched. The experiment will help us understand pathogenesis of brain edema induced by LPS, and provide new measures of therapy for brain edema.METHODS: 50 healthy 1 month-old SD rats whose weight was from 70g to 100g, male or female, were randomly divided into two groups: normal saline group (NS group, n=10), 0.1ml normal saline was injected by carotid for each rat; LPS group (LPS group, n=40), each rat was applied 100μg LPS. LPS group was divided into four groups: 6h, 12h, 24h and 48h. And each group had 10 rats. 5 rats of each group weren't injected EB to carry out immunohistochemistry. Rats were decapitated at different time points, and brain tissue samples were prepared. The water content of brain tissue is determined by measuring both wet weight and dry weight. The EB...